What is Zenitsu's Thunder Breathing sword and what makes it visually distinctive?
Updated Feb 2026
Zenitsu Agatsuma's Nichirin sword in Demon Slayer is a yellow-bladed katana that manifests the Thunder Breathing style he has mastered, despite his apparent inability to consciously use it in normal circumstances. The yellow color of the blade represents the lightning and thunder character of his breathing technique - fast, direct, and electrifying. The sword's most distinctive feature beyond the yellow blade is the tsuba design: a white lightning bolt shape that is immediately recognizable as Zenitsu's weapon. His relationship with his sword is one of the series' running emotional threads - a sword that represents a power he does not believe he has, carried by someone whose unconscious capability far exceeds his conscious confidence. As a display collectible, the Zenitsu katana's yellow blade and lightning tsuba create a striking visual combination that is unlike any other sword in a traditional Japanese collection or even within the broader Demon Slayer replica range.